Abstract: A device for indicating the volume of liquid in a fuel tank or like container includes a linear variable differential transformer (LVDT) mounted within the tank, which is divided into a liquid containing section and a gas containing section by a longitudinally movable piston. Pressure gas is provided to the gas containing section of the tank through a port in a tank wall, and urges the piston to follow the liquid level in the tank. The LVDT has a fixed coil housing with a fixed electrical input and a rotatable core actuator. The core actuator is coupled for rotation in response to movement of the piston. Rotation of the actuator effects translational movement of the core within the coil, thereby producing a variable electrical output in response to changes in liquid volume.

Abstract: In a prover loop used to calibrate positive displacement meters, such as those used on a LACT-unit (Lease Automatic Custody Transfer) in the petroleum industry, a control system is provided for operating the prover loop valve. This control system is designed to operate so that each prover loop test is conducted under identical conditions. The system design permits easy conversion from the conventional hydraulic systems.

Abstract: A temperature-measuring system comprises a thermocouple connectable to a ventional temperature indicator (millivoltmeter) arrangement using the thermoelectric emf, and a length of noise-thermometer conductor (resistor) which is connectable to a noise-thermometer circuit whereby the thermocouple is connected to the noise-thermometer resistor. The system possesses advantages of both the thermoelectric temperature-measuring process and the noise-thermometer measuring process.